Investigation of the Mechanism Causing Baseline shift in Single Stage Quadrupole Mass Spectrometers / vorgelegt von Markus Langner. Wuppertal, September 2023
Inhalt
- List of figures
- Abbreviations
- Introduction
- Short History of Quadrupole Mass Analyzers
- The Beginning of Quadrupole Mass Filters
- The introduction of pre- & post-filters
- First applications of Resonant Excitation
- Tandem Mass Spectrometry involving several QMF
- Frequency Scanning
- Components of a Mass Spectrometer
- The Mass Analyzer
- Detector systems
- Electron Ionization
- Mass Discrimination
- Excited Electronic States of Atoms and Molecules
- Surface reactions of selected particles
- Experimental section
- Results and Discussion
- The Baseline Shift
- General Description
- Ion breakthrough
- Photons
- Dynamic range of the pre-amplifier
- Variation of internal parameters
- Deflection plate potential variation
- Focus lens potential
- Field Axis
- Emission current
- Pressure
- SEM conversion dynode potential
- Extraction voltage
- Rod system potentials
- Type of gas
- Complementary SIMION simulations
- Conclusion of the initial set of experiments
- Photons and Excited species
- Summary and explanation of the narrowed focus
- Remaining hypotheses regarding photons
- Remaining hypotheses about excited species
- Remaining hypotheses about secondary ions
- Theoretical calculations and simulations
- The mechanism behind secondary ionization
- A novel design for the deflection unit
- Summary, Conclusion and Outlook
- References